Thermal interface materials are typically composed of an organic matrix highly loaded with a thermally conductive filler. Thermal conductivity is driven primarily by the nature of the filler, which is randomly and homogeneously distributed throughout the organic matrix. Commonly used fillers exhibit isotropic thermal conductivity and thermal interface materials utilizing these fillers must be highly loaded to achieve the desired thermal conductivity. Unfortunately, these loading levels degrade the properties of the base matrix material (such as flow, cohesion, interfacial adhesion, etc.).
Consequently, the thermal interface material formulator must balance matrix performance with thermal conductivity with the net result being a material with less than optimal thermal conductivity. It is desirable to formulate a thermal interface material with as high a thermal conductivity as possible without sacrificing other physical properties.